A Troll in the War
by novasharp
Summary: One day, Zelretch was bored and decided to get Loki Potter to troll the Fourth War. Beware ye of faint heart. Madness approaches.
1. Prologue

**AN: Loki Potter is from sakurademonalchemist's "Tricksters and Gods" and "Pagans and Angels" stories. Thank you for creating such awesome stories.**

 **Clock Tower, London – Time indeterminate**

It was a bright and sunny day. Somehow, even within the underground Clock Tower, the sun was shining and the birds were singing. In fact, it was such a perfect day that all of the various magi holed themselves up inside their workshops and refused to leave. You see, such a perfect day was surely a sign of impending doom.

As if sensing their trepidation, a shout rang out, "Sooo…bored." And collectively, the entire clock tower shivered. The reason for this fear was that this bored individual was no minor magus, but the Wizard Marshal Zelretch himself, master of the second true magic. When he was bored, terrible things happened to his coincidental targets. In fact, the last group of people who he happened upon while bored were still in the psychological trauma ward.

Fortunately for the sanity of everyone involved, Zelretch happened upon a shaking Lord El-Melloi II. "Tell me, there must be something interesting you can think of," he demanded.

Normally, such an individual would simple pass out in fright at this point. However, Waver Velvet was far braver than most of his comrades. He had survived the deadly, and quite frankly sanity-compromising, events of the Fourth Holy Grail war and even thrived upon the lessons learned from his King. This combined with his recent musings on his friend and King, Iksander, caused him to blurt out "The Fourth War. You can mess with the Fourth War!"

Now, in conjunction with this unlikely and quite fortunate series of events, Zelretch had recently return from the Universal Troll Convention and one person stood out in his mind, the highly entertaining and capable Loki Potter. This, thanking the nervous Waver Velvet, he continued on his way, humming a jaunty tune.

In an unrelated series of events, Waver was thereafter voted the magus of the year, allowing him to gain funding to expand his somewhat-ridiculed education methods, leading to an eventual revolution in the Magus Association's practices which when combined with a series of other seemingly irrelevant events revealed thaumaturgy to the general public and issued in a new golden age of mankind (much to the annoyance of a certain golden king). However that is not important right now, what is important is the poor schmucks in the Fourth Holy Grail war and the chaos about to be unleashed.

 **Colorado Springs, Colorado – 1998**

Loki Potter was enjoying watching the commotion at Stargate Command. Sure, there hadn't been any major issues recently, but all the ongoing missions led to amusing scenarios. Just as he was about to take relax and start playing a round of League with his various friends and Inter-Universal travelers, he felt the arrival of someone directly behind him. After immediately detecting the aura of a fellow master-troll he relaxed and asked, "Hey Zelretch, what brings you here?"

"I am so incredibly bored, but I just found an incredible method to both remove my boredom and cause some major chaos. So, Loki, you free for a while?"

"Well, I am never really needed here and if this is as entertaining as you seem to think it will be, well, I can always return here and now if something important occurs. So, what is you plan?"

"Quite simple, I want you to be a master in the Fourth Holy Grail War."

"…the one with _that_ caster, right?"

"…"

"I thought so. Well, I'll do it. I just need you to provide me with all the information on the function of the ritual. So I can insert myself as a master. Speaking of which, I will definitely summon Caster."

"Okay…this may sting a little."

"Arrrrg, you son of a *****. That was definitely not a little sting. However, thank you for the information. Enjoy the show."

With that Zelretch left to watch the show from his office in the Clock Tower. Loki headed to his ship and informed every one of his plans before attaching the Infinity Bracelet and travelling to 1990, Fuyuki City to set up his base. After that, he would begin his preparations. This would be a grail war to remember.

 **AN: Sorry if the characterization is off.**


	2. Beginnings

**Fuyuki City, Japan – February 12, 1990**

"Is that all, sir?"

"Yeah, thanks. This house is perfect, especially with the property attached."

And it was. Using the vast amount of money stored he had accumulated, Loki had bought a two-story house with plenty of room for guests and a workshop. While it was by no means a mansion, it was quite large for a house in Fuyuki City. With the attached 3 acres, I would allow for great amounts of privacy, and of course a secret underground base. The next issue would be protecting the place. He could use bounded fields, naturally, but those could easily be detected by magi if they were of the necessary strength. Now wards, on the other hand. Wizarding magic had a far greater versatility and metaphysical weight than thaumaturgy, even if it was harder to quantify. Hmm….

"BWAHAHAHAHA," He burst out into maniacal laughter, scaring the poor realtor and any passing bystanders.

"…Sorry, just got a bit excited there. Here's a check to cover the cost. Don't worry, my parents were from old money. Thanks for going the extra distance. You really outdid yourself."

After the realtor had left, he began musing to himself on his future steps, _'Hmm…I should probably contact Zelretch, let him know about the upcoming fun. Maybe I could mess with Lorelei, that always seems to be amusing. Well, I could always screw with upcoming events, ~neh~ Sakura-chan. Such a pity Zouken got her. Well, if Tokiomi is giving her away, I just might find myself an apprentice and a little sister. Fufufufu. Well, that's still three years off. Let's have ourselves a look-see at that grail system, see if we can't ensure we become a master. But first, need to set up those wards.'_

 **-=o=-**

 **Fuyuki City, Japan – February 14, 1990**

In the end, he decided to use one of the ward stones he had from his rewards for the cases back in Britain. Now, how could he control it…. Oh yeah, that work the Asgard had abandoned on technomagic! With Gabriel controlling the wards, the Ley Lines providing the energy, and the versatility of Wizarding magic, he could simulate a Marble Phantasm. Hmm…speaking of Gabriel, now that he had a house he should probably unpack. Taking out Gabriel first, Loki continued unpacking while waiting for the construct to 'wake up' from his trip through Kaliedescope.

"What took you so long to remember me? I thought we were friends….. But don't worry you can make it up by getting me a subscription to World of Warcraft!" Ah. That was the reason why he had waited.

"Go get it yourself if you want it so bad. I need to set up the wards for this place, then tie you in. If you behave, I'll record my meeting with Zelretch and Lorelei. Now help me figure out how to do this. I want to have you be an absolute defense using control over the enclosed environment. Here's the data I have on Marble Phantasms. The Ley Lines should provide sufficient power, but if you need it, I always have that magic generator from that one universe, plus an unlimited power source. Wellll, ~~I'm off to see the Clock Tower!~~"

With that, Loki vanished off to London, leaving Gabriel alone. "Hmm…I should probably finish this, reality control would make an absolute defense, but what else could I add… I really can't wait to see their reactions!"

 **-=o=-**

 **Clock Tower, London, England**

It was a normal day out, meaning wet and dreary. Everyone present felt relieved that the Clock Tower was practically and underground city. Why, they even heard that the Wizard Marshal Zelretch, himself, had finally sat down with Lorelei to review the paperwork. Everything seemed to be going so well. Those poor deluded fools, they have no idea how messed up their day will get. The only people to notice any of this foreshadowing were Zelretch and Lorelei. This is why the vice-director was attempting to speed the meeting along. She was so glad that they had gotten through all that paperwork already. Maybe she could afford a long weekend for the first time in years. She had ensured that they would not be disturbed by picking an out of the way room and layering immense amounts of bounded fields, and so far it seems to be working. Why no one had entered the room and they had been working for the past four hours… Wait a second who is that behind Zelretch. Let's look away, maybe he will disappear and Zelretch will not notice… DAMN YOU ROOT.

" _Fulgur ventus. Fulgur ventus. Fulgur ventus._ Come back here! You will not escape this time Zelretch!"

"She seems really mad, what's wrong with her?" Commented Loki.

"No idea. She just seems to get like that around me. Say, what are you doing here?"

"I'm Loki. Yes, that Loki. No, not this Loki. Yes you're one of my best buds. Want to leave here and talk somewhere quieter?"

"Sure, where to?"

"Allow me." With that, Loki teleported them both away, allowing Lorelei to notice the damage she caused in her chase, reminding her of all the new paperwork this would cause.

"… _ **Damn You Zelretch!**_ "

 **-=o=-**

 **Loki's Lair, Fuyuki City, Japan**

"Okay Zelretch, meet Gabriel, my personal AI. He's helping me figure out my warding scheme. Now, why I came here. Simply put, an alternate of you that I met at the Universal Troll Convention was bored and decided that it would be fun to have me mess with the Fourth Holy Grail War. Oh yeah, and I'm actually also Harry Potter. And I have all the Infinity Gems."

"Bwhuh…? …AHAHAHA. This will be spectacular. All the entertainment I can derive. But wait, isn't the War not for a few years?"

"Don't worry. I am sure we will have plenty of time for pranks. Speaking of which, can I become your apprentice? It will give me an excuse to be seen with you, plus I won't freak out about the crazy training trips."

"Heh. For all the amusement you will create in the future, of course I will take you as an apprentice. Where do you want to go first?"

"Actually, I thought you could help me with my ward scheme."

"…Does that actually?" "Yes." "So he would…" "Yes." "And what about that part?" "Strip…gender select… _GABRIEL!_ "

"Yes Loki?"

"What do you have to say for yourself?"

 _~whistles innocently~_

"… just get rid of it. This ward is serious. Anyhow, here's the video of the reaction. We're headed out again. Yo Zel, want to troll…"

 **-=o=-**

 **===MONTAGE ACTIVATED===**

Over the years that past, Loki rapidly learned the Second Magic as he already had experience with the Multiverse using other methods of travel. He continues his pranking sprees, rapidly becoming feared amongst the Clock Tower. He eventually manages to construct the Marble Phantasm ward, learning enough in the process that he is able to artificially recreate it, earning his slot as the 7th Dead Apostle Ancestor. Eventually, Lorelei calms down enough that he is able to apologize to her by helping with the paperwork as the Zelretch's representative. Perhaps the proudest moment is his heist of Sakura from Zouken.

 **===END MONTAGE===**

 **AN: See you next chapter!**


	3. Plans are Made

**AN: Sorry for the wait.**

 **Paxloria:**

 _In the 'Fate' world, it is not necessary to be a Dead Apostle to be an Ancestor – just be powerful enough and have an open slot. ORT and Primate Murder are the two examples. Also, Loki's element is Magic and his origin is a dual-origin of Change and Chaos._

* * *

 **Loki's Lair, Fuyuki City, Japan – February 21, 1990**

"Zelretch, it's been fun trolling with you this past few weeks, but I need to get back to work. Wonder what Gabriel's been up to? Of course, knowing him, he's probably spent most of the past week surfing the internet. I did modify him to have a connection to my original universe, after all. Well, see ya later!"

"Same here Loki. It was a pleasure."

Walking into his house, he muses, _'Let's see… what to do. My house is all furnished, but I haven't really started working on the wards or protections yet. With my power and work on the wards, I can probably figure out how to reconstruct Marble Phantasm. Rescue Sakura, that's always important, plus the chaos it will cause. Oh yeah, gotta visit Arc, she seems like a fun person. Heh, I let's see if I can become an Ancestor. I can just imagine Lorelei's face. Can't forget my "apprenticeship" with Zel, though. These next few years will be ~~fun~~! Now back to business…'_ "GABRIEL. Get your ass over here!"

"Okie-doki Loki!"

"Goddammit what did I tell you about doing that? Whatever, don't answer that. How's your week been? Made any progress on the ward scheme?"

"Well, I just finished a My Little Pony marathon. But I did come up with some ideas for creative wards. I was reading through the data files on the war and realized that we need a way to prevent people from noticing out property. So, I thought we could create a 'Presence Concealment' ward. Kinda like a modified fidelius. We also need a Magic Absorption ward to prevent stray magic from being detected and absorb magic cast by evildoers. Oh! And an anti-scrying ward, can't forget that!"

"Okay…that actually sounds reasonable. I was also thinking that we should add a selective shield ward along with an alarm ward. Hmm…maybe also add a ward to simulate 'Eye of Mind' in case I have to fight on the property."

"How will I be able to control the wards?"

"You remember all the work the Asgard did on technomagic back in our home dimension?"

"Yeah… Oh! I see, combined with the advancements you made with Tony, you could manage the wards easily."

"Yep. I'll be tying primary control to you. That way I don't have to worry about some of the active wards and magic at the same time. Though that gives me an idea. Gabriel, wanna stop by a Halo universe? Their tech could be pretty useful. Plus stopping the Covanent could be fun!"

"Well, we do have an absurd amount of free time, but first I really think we should get the basic wards down! See how serious I am. I am even giving up Simpsons until we are done."

"Yep, let me just grab a heart stone and some other stuff from my vault and we can start. We can work out the designs when I get back."

 **-=o=-**

 **Loki's Lair, Fuyuki City, Japan – December 14, 1990**

"So, that's done. All we need to do know is figure out that pseudo-Marble Phantasm ward. Meh, we have time. Wanna check out Halo-verse now?"

"Sure Loki! When do you plan on dropping us off?"

"Well…I figure that we could start sometime around 2550 and find the Spirit of Fire. Since I don't really have a combat ship, we can use that! Plus the UNSC will probably be happy to have that ship back."

"Sounds like a plan, just make sure you have all the stuff you need stored in your vault."

"Okay, we'll need to grab some stuff back from the Stargate 'verse. The Asgard owe us one. Maybe they'll let us have some of their tech. Hell, all the UNSC will really need is shields and better FTL tech. We can just give them the latest Goauld stuff."

"Loki, you should probably bring SG-1 along."

"Sure, why not? More fun for me and more fun for them. Plus, they'll really need the help in the future and UNSC tech is much easier to make for now."

 **-=o=- TIMESKIP -=o=-**

 **Loki's Lair, Fuyuki City, Japan – April 7, 1991**

"Well, Gabriel, that was definitely fun! And it helped out friends back at Stargate advance by quite a bit."

Loki had just returned from helping the UNSC win the war. It was immensely amusing to see all the leaders' expressions when they realized just who they were dealing with. Admiral Hood, now that was a good man, it was an honor to meet him. It was so funny to see Cortana try to analyze magic. On the plus side, the UNSC technology (and societal advances) would definitely help the Stargate program defend Earth. A pity they didn't have the resources to manufacture Covanent weaponry. Hah, to see the looks on the faces of those petty false gods when they discovered the true meaning of plasma weaponry.

"So, I assume you got the plans you needed?"

"Yep, I have them on this data card. Once you download them, put them on the holo-projector so we can work on combing them with magecraft. I could provide a power source to power them on their own, but no need to raise too many questions."

" _*whistle*_ That's some impressive stuff. Aside from runes to power these with mana from the ley lines, I don't see many improvements from this world's magecraft. From our original knowledge, and that stuff you adapted from Naruto, however… Think you could manipulate the plasma beams to be multi-phasic. I think most magical shields are limited in their capabilities of blocking dimensional phased attacks."

"Yeah, that's great. If we can take the space-time manipulation capabilities of seals and control them with Japanese runes, we could have a beam composed of randomly phasing sub-beams. That way no shield could fully block it. Well, let's just file this under projects and get back to it later. We have time to prepare. Who do you think I should summon. I know I want Gilgamesh somehow, but I can just combine my powers as Master of Death with my knowledge of Heaven's Feel to summon him. I want him to be more independent anyhow. His main problem was being summoned by that bore Tokiomi. I want a caster because I don't really want that damn Bluebeard being summoned. Maybe I could use Kaleidoscope to summon an alternate of myself? Actually, now that I think about it I should summon Gilgamesh first. He would be helpful, and if he ever got bored, well I'll just have to take him on an adventure. What do you think Gabriel?"

"Personally, I think Gil is hilarious. But first, why don't you summon up his soul before you actually fully summon him?"

"Yeah, that would probably be a good idea. Heh. I forgot I could do this in two parts. Well, here goes. _**Ego dominus concessit potestate mortis unus vocatus e throno aureo rex inter reges. Egredietur Gilgamesh.**_ [1]"

The symbol of the Deathly Hallows appeared before Loki, glowing golden from the power it was consuming. As the chant finished a brilliant flash of golden light occurred, before clearing. Before him now stood the spirit of Gilgamesh (who for convenience we shall henceforth refer to as Gil).

"What mongrel dares summon the King of Heros? What impudence is this?" demanded the golden-clad figure.

Not feeling like allowing a rant to begin, Loki quickly cut in, "I am Loki Laufeyson, one of the Æsir, but originally a Jötunn. I will be fighting in the war, both for my amusement and that of a cranky old vampire. I figured the throne must get a bit boring after eternity, so maybe I spice things up by summoning you as a true heroic spirit. In return, I would like you to help me with my efforts."

"YOU MONGREL! You dare command the king?!"

"Well, if you don't want to help, I can just send you back to your throne. Besides, currently you are just a spirit. Well, your full spirit if you want to be technical, but nevertheless, that means you cannot affect the world right now. So, do you want in?"

"Hmph…you should be grateful that I have been bored. I will deign to assist you, but you must ensure that I am entertained or you shall know my wrath."

"Okay. Thanks. However, you'll have to chill in that form for a bit. I didn't really want to make all the preparations, then have you refuse. I could do it now, but you'd just be in the body of a Servant. Before I start, though, there are several other things you will probably want to know. The world of today is generally pretty boring and there are still four years until the ritual. Fortunately, I am a master of Kaleidoscope (and all the other True Magics), so I can just take you to entertaining dimensions. Also, when in public, nobody will know who you are, so don't get pissy if a bunch of people don't treat you with respect. Lastly, modern day has video games, which are incredible even if most of the rest of the world is boring." ***SHATTER*** "Anyhow, you awesome readers, that will be all for now. Maybe some of our adventures will come up in the future as 'Interludes' or 'Omakes,' but right now, it would be a bit tedious to watch. See y'all in two years or so." ***"WHY DID YOU HAVE TO BREAK THE FOURTH WALL? ARE YOU TRYING TO IMITATE DEADPOOL? AH WELL, TIMESKIP"***

* * *

 ***Gilgamesh was promptly introduced to the wonders of the modern world (some of them procured using our friendly Second Magic user) like video games, the internet, anime, and movies (During which he became addicted to 4X games) The intervening years were filled with mischief and mayhem and adventure (which will quite likely be added as interludes), but now we return to Fuyuki to continue the story.***

* * *

 **Loki's Lair, Fuyuki City, Japan – May 4, 1993**

It was a bright and sunny day and children were playing out in the parks while their parents relax in the shade. However unseen gears were turning and lives were about to be shaken. Here, along the Miyama River, we come across Gilgamesh walking with Harry "Loki" Potter.

"So Gil, it's coming up on the two-year anniversary of your summoning. How are you enjoying the modern world?"

"Hmpf…I have come to tolerate these mongrels as they scurry about. I can finally see the faintest glimmerings of potential within their petty actions."

"That must have been hard for you to say. But don't worry, I have seen humanities future in some realms and it is astonishing."

"So you tell me. Why then do you keep refusing to show me this world."

"Well…it's my home dimension and I kinda had a falling out with my father, so don't really want to touch that mess of paranoia with a ten-foot pole."

"Hmpf, very well. What is our purpose for this walk today? You are not normally so foolish as to drag the rightful king away from his imminent victory in glorious battle against alien scum."

"Well, I don't know the exact date, but soon Sakura Tohsaka will be sent to the Matou family. One of my self-set tasks is to rescue her from her fate. I have no desire to let that filthy degenerate work Zouken lay his hands on her. His family, but more specifically Zouken himself, uses crest-worm familiars. No one, least of all an innocent child, deserves that fate. And for his crimes, Zouken must pay."

"I am sure you have already thought out a plan. Share it with me before my patience for your grandstanding expires."

"Sheesh, you really need to learn to relax. But yes, I do have a plan. Sometime before-hand, I will establish a 'void' bounded field that prevents prana from entering or leaving while preventing the field itself from being sensed. Then, on the day of the transfer, we will hid (yes, you must also hide) in the house waiting for Zouken to return. Yes, I will make sure to mask our presence. Once Zouken arrives and puts Sakura into her room after showing here the worm pit, we will bind Zouken, destroy all his familiars, and exorcise him. We will then replace Zouken with a homunculus that I will create."

"And about rescuing the girl?"

"We will talk to her in the morning. We also need to call her Uncle Kariya to let him know."

"I will trust in your plan."

 **AN: That's all for now, but I will try to update more regularly from here. Next chapter will probably start the morning after, when Sakura wakes up.**


End file.
